I have a PC which runs DEBIAN Linux. This was created about 6 years ago, not by me.

Recently, USER logins have ceased to work; when you log in (enter login name and password) the screen goes black for a few seconds then the login prompt screen is returned again. This can be repeated indefinitely.

It is still possible to login to ROOT.

I have tried resetting passwords and creating new users but, non of this has fixed the problem.

I'm looking for solutions, ideas, suggestions --- please.

I bet you have exhausted disk space.
df -lh will show the numbers. Any disk partition near of 100% could be a problem.
In special, /var and / partitions cannot be full, because the system needs space to make logs about a regular user logging into the system.

this is just a long shot, of course.

good point - most file systems reserve some space for root to working.


perhaps /home is at 100% used.

Thank you guys. It WAS a 100% full disk. I've recovered 35Mb of space and user login works again.

If you have any suggestions as to what might be safely deleted from the Linux system directories, this would be helpfull also.

well, the 1st thing to go has to be things in user's trash can(s) - including root in /root.

trimming down syslog and other log files (or blanking them). in /var.

purge packages that are being kept by the system after removal (check atp-get man page or web). delete old iso images taht you don't need. remove unsed kernel source in /usr/src.

Wow, you guys are amazing. I could never guess that right just by failed user logins!

I have a LOT to learn...

also go to / type

"du -x |sort -nr|more"

then you have where all the space is being taken up.


then you can do that in individual directories.

how is your disk partitioned?


well the fact that root can log in gives it a away a bit - file systems reserve some space for root to work in. the fact that normal user's can't log in but root can indicated that you've reached a disk full state. the reason it does this, you've just seen. if root couldnt log in or do anything, you would be in big trouble!

well, could use a live cd - you should always have one around....

My first thought was that they might be using NIS authentication and the computer running as an NIS server was down. I was way off!

is the machine in a NIS network??

I have no idea... that's why I could only suspect it might have been the case.

type 'ypwhich' as root. that should throw some light...

Now that the problem has been solved, I doubt the OP is still reading this thread...